ATLANTA -- The government says Americans -- especially women -- are getting fatter. And federal health researchers say carbohydrates are the biggest culprit.

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A report Centers for Disease Control and Prevention found that obesity rates increased from 14.5 percent in 1971 to 30.9 percent in 2000.

Compared to 30 years ago, women are eating 335 more calories a day, the equivalent of a large chocolate chip cookie. Men have been eating more, too -- their intake since 1971 has increased by 168 calories, or the equivalent of a 12-ounce can of cola.

The study says increased carb consumption accounts for a large measure of those extra calories. Other factors include an increase in eating out, larger serving sizes, and more consumption of salty snacks, soft drinks and pizza.

To arrive at the findings, the CDC collected self-reported data from thousands of Americans from 48 states.

The idea that carbohydrates contribute to larger waistlines was popularized by the late Dr. Robert Atkins, whose diet has millions of followers.

But CDC officials said people should watch their overall eating and exercise habits -- not just carbs.

Study Details